Threatened medicinal tree 'should be domesticated'

[NAIROBI] A threatened tree used for curing prostate disorders could be saved from extinction through domestication, according to scientists who examined the trees in different regions of Kenya.

Prunus africana is a highland forest tree found in some African countries, mostly Kenya, the Democratic Republic of Congo, and the Zambezi basin divide.

Extracts from its bark have been used to treat certain prostate disorders, but overexploitation has left the tree vulnerable to extinction.

The existence of this species in its natural wild habitat is threatened by "unsustainable and unchecked exploitation" according to Peter Gachie, a scientist at the World Agroforestry Center (ICRAF), in Nairobi, Kenya, and lead author of the study.

His team at ICRAF examined which types of P. africana have the highest yields of bark extracts — a first step towards domestication of the trees.

In the study, published in the latest issue of Forest, Trees and Livelihood, they compared the yields of medicinal bark extract of P. africana from different Kenyan forest zones and found the highest yields in medium-sized trees; the yield was also higher in trees growing at higher altitudes and cooler temperatures.

This knowledge could be used to choose "good sources of planting material" for domesticating the trees, they said.

"Cultivating the tree on farms will assist in its regeneration, improve on its growth and regulate its harvesting," Gachie told SciDev.Net.

He added that spreading awareness about the trees' medicinal use and vulnerability to extinction could stimulate demand for its cultivation.

Francis Gachathi, a senior scientist at the Kenya Forest Research Institute, said that rising demand for the tree bark is endangering it in the wild.

He said that its cultivation will not only help counter unsustainable exploitation but also help address the escalating demand for therapy in what is increasingly becoming a major health problem internationally.

"Unrestricted export of this forest product should not be allowed," he said.

The paper concludes that more research is needed on the effect of habitat on medicinal extract yields and on how the yields may change if trees are planted in different habitats. The diversity of the species is important for breeding purposes and should be conserved, it says.

The need for conservation of P. africana was also highlighted in a modelling study published last month (31 March) in African Journal of Ecology. It found the species was highly vulnerable to a warming climate.